20 November 2008

JAXA (Japanese Space Agency) has completed the primary mission of the lunar probe Kayuga. Since the craft is still operational, JAXA plans to continue operating it, much like with any other probe.

For its primary mission, Kaguya circled the Moon in a polar orbit at 100 km above the lunar surface, the same as Chandrayaan-1. The extended mission entails reducing the altitude by half to 50 km. Then in May of next year, it will shift into an highly elliptical orbit. Apogee, or apolune when talking about the Moon will be back at 100 km. Perilune, the closest point of approach, will be an eye-popping 20 km. This will take place over the south polar feature Aitken Basin, a target for outpost locations. Normally, an orbital height of 20 km wouldn't matter for an airless body like the Moon, but because the Moon has an irregular gravity field, due mostly to Mascons, a 20 km orbit is unstable and Kayuga is expected to crash into the Moon.